/*
 * IE/TLV fragmentation/defragmentation support for
 * Broadcom 802.11bang Networking Device Driver
 *
 * Copyright (C) 1999-2019, Broadcom.
 *
 *      Unless you and Broadcom execute a separate written software license
 * agreement governing use of this software, this software is licensed to you
 * under the terms of the GNU General Public License version 2 (the "GPL"),
 * available at http://www.broadcom.com/licenses/GPLv2.php, with the
 * following added to such license:
 *
 *      As a special exception, the copyright holders of this software give you
 * permission to link this software with independent modules, and to copy and
 * distribute the resulting executable under terms of your choice, provided that
 * you also meet, for each linked independent module, the terms and conditions
 * of the license of that module.  An independent module is a module which is
 * not derived from this software.  The special exception does not apply to any
 * modifications of the software.
 *
 *      Notwithstanding the above, under no circumstances may you combine this
 * software in any way with any other Broadcom software provided under a license
 * other than the GPL, without Broadcom's express prior written consent.
 * $Id$
 *
 * <<Broadcom-WL-IPTag/Open:>>
 */

#include <bcmutils.h>
#include <frag.h>
#include <802.11.h>

/* defrag a fragmented dot11 ie/tlv. if space does not permit, return the needed
 * ie length to contain all the fragments with status BCME_BUFTOOSHORT.
 * out_len is in/out parameter, max length on input, used/required length on
 * output
 */
int bcm_tlv_dot11_defrag(const void *buf, uint buf_len, uint8 id, bool id_ext,
                         uint8 *out, uint *out_len)
{
    int err = BCME_OK;
    const bcm_tlv_t *ie;
    uint tot_len = 0;
    uint out_left;

    /* find the ie; includes validation */
    ie = bcm_parse_tlvs_dot11(buf, buf_len, id, id_ext);
    if (!ie) {
        err = BCME_IE_NOTFOUND;
        goto done;
    }

    out_left = (out && out_len) ? *out_len : 0;

    /* first fragment */
    tot_len = id_ext ? ie->len - 1 : ie->len;

    /* copy out if output space permits */
    if (out_left < tot_len) {
        err = BCME_BUFTOOSHORT;
        out_left = 0; /* prevent further copy */
    } else {
        memcpy(out, &ie->data[id_ext ? 1 : 0], tot_len);
        out += tot_len;
        out_left -= tot_len;
    }

    /* if not fragmened or not fragmentable per 802.11 table  9-77 11md0.1 bail
     * we can introduce the latter check later
     */
    if (ie->len != BCM_TLV_MAX_DATA_SIZE) {
        goto done;
    }

    /* adjust buf_len to length after ie including it */
    buf_len -= (uint)(((const uint8 *)ie - (const uint8 *)buf));

    /* update length from fragments, okay if no next ie */
    while ((ie = bcm_next_tlv(ie, &buf_len)) &&
           (ie->id == DOT11_MNG_FRAGMENT_ID)) {
        /* note: buf_len starts at next ie and last frag may be partial */
        if (out_left < ie->len) {
            err = BCME_BUFTOOSHORT;
            out_left = 0;
        } else {
            memcpy(out, &ie->data[0], ie->len);
            out += ie->len;
            out_left -= ie->len;
        }

        tot_len += ie->len + BCM_TLV_HDR_SIZE;

        /* all but last should be of max size */
        if (ie->len < BCM_TLV_MAX_DATA_SIZE) {
            break;
        }
    }

done:
    if (out_len) {
        *out_len = tot_len;
    }

    return err;
}

int bcm_tlv_dot11_frag_tot_len(const void *buf, uint buf_len, uint8 id,
                               bool id_ext, uint *ie_len)
{
    return bcm_tlv_dot11_defrag(buf, buf_len, id, id_ext, NULL, ie_len);
}
